1. Field of the Invention
The present invention relates to a disc cartridge housing a disc such as optical disc.
2. Description of the Related Art
In the past, there are widely used disc cartridges each of which has a disc-shaped recording medium such as optical disc housed rotatably in a body thereof and is to be loaded in a disc recording and/or playback apparatus with the disc-shaped recording medium being kept housed in the cartridge body. The disc cartridge of this type can protect the disc-shaped recording medium housed therein and facilitate loading and unloading of the disc-shaped recording medium into and from the disc recording and/or playback apparatus.
To enable write and/or read of information signals to and/or from the above disc cartridge loaded in a disc recording and/or playback apparatus with the disc-shaped recording medium being kept housed in the body of the disc cartridge, the disc cartridge has formed in the body thereof a driving aperture through which the disc-shaped recording medium is to face a turn-table included in a disc rotation driving mechanism that rotates the disc-shaped recording medium, and a write and/or read aperture through which the signal recording area of the disc-shaped recording medium is partially exposed to outside in a range between inner and outer radii thereof.
The disc cartridge housing the disc-shaped recording medium has provided thereon a shutter member that opens and closes at least the write and/or read aperture to prevent dust or the like from entering the cartridge body and contaminating the disc-shaped recording medium.
There is also available a disc cartridge in which the shutter member is always forced by a forcing member such as a spring or the like in a direction to close the write and/or read aperture in order to prevent the write and/or read aperture from inadvertently being opened and a foreign matter such as the user's finger or the like from entering through the aperture to scratch the disc-shaped recording medium in the disc cartridge not loaded in any disc recording and/or playback apparatus, for example, during storage.
Also, there have been proposed in the Japanese Patent Application Laid Open No. 212872 of 1991 and Japanese Utility Model Application Laid Open No. 83274 of 1987 disc cartridges in which for easier fixation of a spring member that forces the shutter member, the spring member is provided integrally with the shutter member so that it can be fixed to the cartridge body simultaneously with installation of the shutter member to the cartridge body.
In the disc cartridge disclosed in the above Japanese Patent Application Laid Open No. 212872 of 1991, since the shutter member is only forced by the spring member in a direction to close the write and/or read aperture, if the user tries to move the shutter member by holding with the finger or the like against the force of the spring member, the shutter member will easily be moved in a direction to open the write and/or read aperture.
The disc cartridge disclosed in the Japanese Utility Model Application Laid Open No. 83274 of 1987 further includes a shutter movement limiting member to lock the shutter member having been moved to a position to close the write and/or read aperture. In this disc cartridge, the shutter member is thus locked by the shutter movement limiting member and can positively close the write and/or read aperture. However, since the shutter movement limiting member is installed to the cartridge body independently of the shutter member, it will add the number of parts of the disc cartridge and make the assembling work more complicated. Also, the cartridge body should have an inner space for installation of the shutter movement limiting member, which will make it difficult to design the disc cartridge itself smaller.